The present invention relates generally to an air compressor system and more particularly to an integrated air/oil separator tank and oil-flooded air compressor.
An illustrative prior art compressor assembly is shown in FIG. 1. In conventional air compressor systems which utilize an oil-flooded compressor 10, air is compressed in a compression chamber 14 or airend within a compressor housing 12 by a set of rotary screws 16, 18. Each rotary screw 16, 18 is supported by a pair of end bearings 20, 22 and 24, 26, respectively. One end of the compressor housing 12 is open to allow the rotors 16, 18 to be positioned in the compression chamber 14. A secondary housing 32 is configured to close the compressor housing 14 once the rotors 16, 18 are installed. The secondary housing 32 includes bores to receive two of the bearing assemblies 22 and 26 which are inserted as indicated by arrow B in FIG. 1. A cover plate 34 is then attached to the secondary housing 32 to close the bores. The opposite end of the compressor housing 12 has a pair of bores to receive the bearings 20 and 24 which are inserted as indicated by the arrow A in FIG. 1. A secondary cover plate 30 is attached to compressor housing 12 to cover the bores. Each connection of a cover to a housing or a housing to a housing provides a potential leak path.
In an oil-flooded compressor, a lubricant, such as oil, is injected into the compression chamber 14 and mixes with the compressed air. The oil is generally injected into the compression chamber 14 for a number of reasons including cooling the air compressor system, lubricating bearings, balancing axial forces and sealing the rotary screws 16, 18. Although using oil is essential for operating these types of air compressor systems, the oil must be removed from the stream of compressed air before the compressed air may be used downstream for pneumatic equipment and/or other tools.
Thus, in such conventional air compressor systems, the compressed air and oil mixture discharged from the airend of the compressor flows with a high velocity into a separator tank 40 where the air and oil of the air/oil mixture are caused to separate. Separator tanks 40 are usually cylindrical tanks mounted either vertically or horizontally. In vertically mounted separator tanks 40, the air/oil mixture is directed tangentially around an inner wall of a separation chamber. The combination of the centrifugal forces acting on the air/oil mixture and contact between the air/oil mixture and the inner wall of the separation chamber causes much of the oil to separate from the air/oil mixture, thereby allowing gravity to draw the oil downwardly into a lower portion of the separation chamber and also allowing the air to separate from the oil and flow upwardly in the separation chamber. In horizontally mounted separator tanks 40, the air/oil mixture enters at high speed and collides with the end wall of the tank. The air/oil mixture then flows in the opposite direction at a slower velocity due to an increase in diameter. The impingement followed by a slowed velocity allows gravity to draw the oil downwardly into a lower portion of the separation chamber. Both of these types of separation effects are known in the art as primary separation.
As generally known, an air/oil separator tank 40 for an oil-flooded air compressor system generally provides two functions. The separator tank 40 provides a means to separate oil from the air/oil mixture introduced into the separation chamber as described above and it also functions as an oil sump for the compressor system.
Conventional air compressor systems as described above include multiple hoses 42, tubes, pipes or the like and associated fittings connecting a compressor 10 to a separator tank 40. Hoses 42 and associated fittings provide potential leak paths which, if developed, could adversely affect the overall operation of the compressor system. Using hoses 42 and associated fittings also requires additional assembly time. Thus, there is a need for an air compressor system which eliminates or at least reduces the number of hoses and associated fittings used to connect a compressor to a separator tank.
Additionally, since conventional air compressor systems use a hose 42, typically a flexible hose, to connect the compressor 10 to a separator tank 40, the compressor 10 and the separator tank 40 are not securely attached as a single unit, thereby making it virtually impossible to maneuver the entire compressor system as one. In addition, since the compressor 10 and the separator tank 40 are individual units, each is provided with its own isolation or supporting mounts, thereby adding undesirable cost to the overall compressor system. Thus, there is a need for an air compressor system which is easier to handle and which is assembled together in such a way that the entire compressor system can be handled or moved as a single unit, and which is also mountable to an associated subbase, so as to provide a more cost effective compressor system.